Justice Department lawyers have argued that the president’s Twitter handle was a personal account, not a governmental one

A federal appeals court in New York on Tuesday weighed whether President Trump’s practice of blocking some users on Twitter violates the free-speech protections of the First Amendment.

The arguments, made before a three-judge panel from the Second U.S. Circuit Court of Appeals, stemmed from a 2017 lawsuit filed by Columbia University’s Knight First Amendment Institute on behalf of seven people who had been blocked by the president’s @realDonaldTrump account. The plaintiffs included a Maryland sociology professor, a New York...